Bipolar forceps having monopolar extension

ABSTRACT

An endoscopic forceps for treating tissue includes a housing having a shaft affixed thereto which has first and second jaw members attached to a distal end thereof. The forceps also includes an actuator for moving jaw members relative to one another from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each of the jaw members is adapted to connect to a source of electrosurgical energy such that the jaw members are selectively capable of operating in a bipolar mode which enables the jaw members to conduct bipolar energy through tissue held therebetween to treat tissue. The forceps also includes a monopolar element housed within the first jaw member and integrally associated with the knife. The monopolar element is selectively movable from a first position within the first jaw member to a second position distal to the first jaw member. The monopolar element is adapted to connect to the source of electrosurgical energy such that the monopolar element is selectively activateable independent of the bipolar mode.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to U.S. ProvisionalApplication Ser. No. 60/520,579 file on Nov. 17, 2003 by Lawes et al.Entitled “BIPOLAR FORCEPS HAVING MONOPOLAR EXTENSION” the entirecontents of which being incorporated by reference herein.

BACKGROUND

The present disclosure relates to an electrosurgical forceps and moreparticularly, the present disclosure relates to an endoscopic bipolarelectrosurgical forceps for coagulating, sealing and/or cutting tissuehaving a selectively energizable and/or extendable monopolar extensionfor enhanced electrosurgical effect.

TECHNICAL FIELD

Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue. As an alternative toopen forceps for use with open surgical procedures, many modern surgeonsuse endoscopes and endoscopic instruments for remotely accessing organsthrough smaller, puncture-like incisions. As a direct result thereof,patients tend to benefit from less scarring and reduced healing time.

Endoscopic instruments are inserted into the patient through a cannula,or port, which has been made with a trocar. Typical sizes for cannulasrange from three millimeters to twelve millimeters. Smaller cannulas areusually preferred, which, as can be appreciated, ultimately presents adesign challenge to instrument manufacturers who must find ways to makeendoscopic instruments that fit through the smaller cannulas.

Many endoscopic surgical procedures require cutting or ligating bloodvessels or vascular tissue. Due to the inherent spatial considerationsof the surgical cavity, surgeons often have difficulty suturing vesselsor performing other traditional methods of controlling bleeding, e.g.,clamping and/or tying-off transected blood vessels. By utilizing anelectrosurgical scissors, the surgeon may cut tissue during a givensurgical procedure utilizing a combination of mechanical cutting actionand electrosurgical cutting. By utilizing an endoscopic electrosurgicalforceps, a surgeon can cauterize, coagulate/desiccate and/or simplyreduce or slow bleeding simply by controlling the intensity, frequencyand duration of the electrosurgical energy applied through the jawmembers to the tissue.

For treating larger vessels, a surgeon may opt to seal the tissue orvessel. Tissue sealing is fundamentally different than simplycoagulating or cauterizing vessels. For the purposes herein,“coagulation” is defined as a process of desiccating tissue wherein thetissue cells are ruptured and dried. “Vessel sealing” or “tissuesealing” is defined as the process of liquefying the collagen in thetissue so that it reforms into a fused mass with limited demarcationbetween adjacent tissue structures. In order to effectively seal largervessels (or tissue) two predominant mechanical parameters must beaccurately controlled—the pressure applied to the vessel (tissue)preferably about 3 kg/cm² to about 16 kg/cm² and the gap distancebetween the electrodes preferably about 0.001 inches to about 0.006inches. Several examples of endoscopic vessel sealing instruments aredisclosed in commonly-owned U.S. patent application Ser. Nos.10/116,944, 10/179,863, 10/369,894 and 10/180,926 and PCT/US01/11340 theentire contents of all of which are hereby incorporated by referenceherein.

Generally, the electrical configuration of electrosurgical forceps canbe categorized in two classifications: 1) monopolar electrosurgicalforceps; and 2) bipolar electrosurgical forceps. Monopolar forcepsutilize one active electrode associated with the clamping end effectorand a remote patient return electrode or pad which is attachedexternally to the patient. When the electrosurgical energy is applied,the energy travels from the active electrode, to the surgical site,through the patient and to the return electrode.

Bipolar electrosurgical forceps utilize two generally opposingelectrodes which are disposed on the inner opposing surfaces of endeffectors and which are both electrically coupled to an electrosurgicalgenerator. Each electrode is charged to a different electric potential.Since tissue is a conductor of electrical energy, when the effectors areutilized to grasp, seal or cut tissue therebetween, the electricalenergy can be selectively transferred through the tissue.

One of the inherent disadvantages to utilizing a bipolar endoscopicforceps for cauterizing, coagulating cutting or sealing vessels andother tissues is the inability of the bipolar forceps to match thebenefits or advantages of monopolar instruments (i.e., monopolarinstruments have the ability to move through avascular tissue anddissect through narrow tissue planes) necessitating the need for thesurgeon to replace the bipolar forceps during surgery to reap thebenefits of using the monopolar instrument for certain applications.Likewise, during some monopolar endoscopic applications it may beadvantageous to replace the monopolar instrument with a bipolar forceps,e.g., for sealing large tissue structures. For example, during acholecystectomy the gallbladder is dissected from the liver which wouldtypically entail using an endoscopic monopolar instrument, e.g.,electrosurgical blade, electrosurgical pencil, loop electrode, etc.However, during the cholecystectomy procedure there may also be a needto seal the cystic duct or cystic artery which may require a bipolarvessel sealing instrument necessitating the need to replace themonopolar instrument. The surgeon may need to repeatedly remove themonopolar instrument from the operating cavity to utilize the bipolarinstrument and vice versa.

Thus there exists a need to develop an instrument which can combine thebenefits of both monopolar and bipolar operation thereby reducing theneed for the surgeon to substitute instruments during surgical certainprocedures.

SUMMARY

The present disclosure relates to an endoscopic forceps for treatingtissue and includes a housing having a shaft affixed thereto and firstand second jaw members attached to a distal end of the shaft. Theforceps also includes an actuator for moving jaw members relative to oneanother from a first position wherein the jaw members are disposed inspaced relation relative to one another to a second position wherein thejaw members cooperate to grasp tissue therebetween. A source ofelectrosurgical energy is connected to each jaw member such that the jawmembers are selectively capable of operating in a bipolar mode whichenables the jaw members to conduct bipolar energy through tissue heldtherebetween to treat tissue. The forceps also includes a monopolarelement housed within at least the first jaw member which is selectivelymovable from a first position within the first jaw member to a secondposition distal to the first jaw member. The monopolar element isconnected to the source of electrosurgical energy and is selectivelyactivateable independent of the jaw members.

In one embodiment according to the present disclosure, the forcepsincludes a knife which is selectively moveable within a knife channeldefined within at least one of the first and second jaw members to cuttissue disposed between the first and second jaw members.Advantageously, a knife actuator allows a user to selectively move theknife to cut tissue disposed between the jaw members. The source ofelectrosurgical energy carries electrical potentials to each respectivejaw member such that the jaw members are capable of conducting bipolarenergy through tissue held therebetween to effect a tissue seal.

Advantageously, the knife is designed to initially cut tissue disposedbetween the first and second jaw members and subsequently extenddistally from the jaw members to treat tissue in a monopolar fashion.Preferably, the forceps includes a safety (e.g. a safety circuit ormechanical safety element) which only allows electrical activation ofthe knife (or monopolar element) when the knife (or monopolar element)is extended from the distal ends of the jaw members. The safety may alsodeactivate the jaw members through circuitry or utilizing a mechanicalsafety element.

In one embodiment, the first jaw member and the second jaw member eachinclude an elongated slot which runs in opposition substantially alongthe respective lengths thereof such that the two opposing elongatedslots form the knife channel for reciprocating the knife to dividetissue disposed between the two jaw members.

In another embodiment, the forceps is a vessel sealing forceps and atleast one of the jaw members includes at least one non-conductive stopmember disposed thereon which controls the distance between the firstand second jaw members when tissue is held therebetween. Advantageously,the stop member(s) maintains a gap distance of about 0.001 inches toabout 0.006 inches between the jaw members when tissue is compressedbetween the jaw members.

In yet another embodiment according to the present disclosure, theforceps includes an actuator which operates to both move the knife tocut tissue disposed between jaw members and to extend the knife or aseparate monopolar element from the first position within the first jawmember to the second position distal to the first jaw member. In stillyet another embodiment according to the present disclosure, the forcepsincludes an actuator which operates to both move the jaw membersrelative to one another from the first to second positions to grasptissue therebetween and to extend the monopolar element from the firstposition within the first jaw member to the second position distal tothe first jaw member.

In another embodiment according to the present disclosure, a firstactuator may be designed to operate the jaw members for grasping tissueand a second actuator may be included which operates to extend themonopolar element from the first position within the first jaw member tothe second position distal to the first jaw member.

The present disclosure also relates to an endoscopic forceps whichincludes a housing having a shaft affixed thereto and first and secondjaw members attached to a distal end of the shaft. The first jaw memberis configured to extend distally relative to the second jaw member. Aactuator is includes for moving jaw members relative to one another froma first position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw memberscooperate to grasp tissue therebetween. The jaw members are connected toa source of electrosurgical energy such that the jaw members areselectively capable of operating in a bipolar mode which enables the jawmembers to conduct bipolar energy through tissue held therebetween.

The forceps also includes a control switch which, upon selectiveactivation, deactivates the second jaw member and activates the firstjaw member with a first electrical potential. At relatively the sametime, the control switch also activates a return electrode or return padwith a different electrical potential which is placed adjacent to thepatient to enable the first jaw member to selectively treat tissue in amonopolar fashion. Preferably, a safety is included which limitselectrical activation of the control switch to when the jaw members aredisposed in the second position.

The present disclosure also relates to an endoscopic forceps whichincludes a housing having a shaft affixed thereto. The shaft includesfirst and second jaw members attached to a distal end thereof.Preferably, the first and second jaw members each include a tapered orelongated distal end. The forceps also includes an actuator for movingjaw members relative to one another from a first position wherein thejaw members are disposed in spaced relation relative to one another to asecond position wherein the jaw members cooperate to grasp tissuetherebetween. A source of electrosurgical energy is connected to eachjaw member such that the jaw members are selectively capable ofoperating in a bipolar mode which enables the jaw members to conductbipolar energy through tissue held therebetween.

A control switch is also included which, upon selective activationthereof, activates the first jaw member and the second jaw member with afirst electrical potential and activates a return electrode with adifferent electrical potential. The return electrode is preferablyplaced adjacent to the patient which enables the first and second jawmembers to selectively treat tissue in a monopolar fashion. Preferably,the forceps includes a safety which only allows electrical activation ofthe control switch when the jaw members are disposed in the secondposition.

In another embodiment of the present disclosure, the actuator isselectively lockable to maintain a closure pressure in the range ofabout 3 kg/cm² to about 16 kg/cm² and, preferably, about 7 kg/cm² toabout 13 kg/cm² between the jaw members which is advantageous inproducing effective and reliable tissue seals. In yet anotherembodiment, the forceps may also include a rotating assembly forrotating the jaw members about a longitudinal axis defined through theshaft. Advantageously, the forceps includes a unilateral jaw assembly,i.e., the first jaw member is movable relative to the second jaw memberand the second jaw member is substantially fixed. Attentively, theforceps may include a bilateral jaw assembly, i.e., both jaw membersmove relative to one another.

Preferably, a spring is included with the actuator or drive assembly tofacilitate actuation of the movable handle and to assure the closureforce is maintained within a working range of about 3kg/cm² to about 16kg/cm².

In yet another embodiment, the monopolar element is housed within atleast the first jaw member and is integrally associated with the knife.In this particular embodiment, the monopolar element is selectivelymovable with the knife from a first position within the first jaw memberto a second position distal to the first jaw member. Preferably, theknife channel includes a first knife channel defined within one of thejaw members and a second knife channel disposed within the other of thejaw members wherein the second knife channel is wider than the firstknife channel to allow reciprocation of the monopolar elementtherethrough.

Preferably, the first jaw member includes an aperture defined in thedistal end thereof which permits selective distal translation of themonopolar element therethrough for monopolar treatment of tissue. Asafety may also be included which only allows electrical activation ofthe monopolar element when the monopolar element is extended from thedistal end of the first jaw member. Preferably, a trigger operates tomove both the knife to divide tissue disposed between the jaw membersand to extend the monopolar element from the first position within thefirst jaw member to the second position distal to the first jaw member.

The present disclosure also relates to a method for treating tissue withelectrosurgical energy from an electrosurgical generator which includesthe steps of: providing an endoscopic forceps including a housing havinga shaft affixed thereto. The shaft includes first and second jaw membersattached to a distal end thereof. An actuator is included for moving jawmembers relative to one another from a first position wherein the jawmembers are disposed in spaced relation relative to one another to asecond position wherein the jaw members cooperate to grasp tissuetherebetween. A monopolar element is also included which is housedwithin at least the first jaw member and selectively movable from afirst position within the first jaw member to a second position distalto the first jaw member. A return electrode is provided and placed incontact with patient tissue.

The method also includes the steps of: connecting to each jaw member,the monopolar element and the return electrode to the electrosurgicalgenerator; grasping tissue between the jaw members; selectivelyactivating the jaw members to treat tissue disposed between the jawmembers in a bipolar fashion; and selectively activating the monopolarelement and the return electrode independent of the jaw members to treattissue in a monopolar fashion.

Preferably, after the step of selectively activating the jaw members totreat tissue, the method includes the step of: extending the monopolarelement from the distal end of the jaw members. Advantageously, the stepof selectively activating the monopolar element includes deactivatingthe jaw members.

After the step of selectively activating the jaw members to treattissue, the method may include the step of: releasing the tissue fromthe jaw members.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a side view of an endoscopic forceps showing a housing, ashaft, an end effector assembly and a trigger assembly in a firstposition according to the present disclosure;

FIG. 1B is an enlarged, cross section taken along line 1B-1B of FIG. 1A;

FIG. 1C is an enlarged, side view of the trigger assembly of FIG. 1A;

FIG. 1D is an enlarged, side view of the embodiment of an end effectorassembly of FIG. 1A showing relative extension of a monopolar elementfrom a distal end of the end effector assembly;

FIG. 2 is a side view of the trigger assembly is a second position foradvancing a knife within the end effector assembly;

FIG. 3 is a side view of the trigger assembly in a third position forextending a monopolar element from a distal end of the end effectorassembly;

FIG. 4 is a side view of an alternate embodiment of the presentinvention showing a second actuator advancing the monopolar elementrelative to the distal end of the end effector assembly;

FIG. 5A is an enlarged, side schematic view of one embodiment of an endeffector assembly showing relative movement of a first jaw memberrelative to a second jaw member prior to advancement of the knifethrough the end effector assembly;

FIG. 5B is an enlarged, side schematic view of the end effector assemblyshowing relative movement of the knife through the end effector assemblyto divide tissue;

FIG. 5C is an enlarged, side schematic view of the end effector assemblyshowing relative movement of the knife extending from the distal end ofthe end effector assembly;

FIG. 6A is an enlarged, side schematic view of another embodiment of anend effector assembly showing a first or upper jaw member extendingbeyond a second or lower jaw member;

FIG. 6B is schematic view of another embodiment of an end effectorassembly showing a series of electrical connections to a control switchand a generator to enable both bipolar activation and monopolaractivation;

FIG. 6C is a table showing the various modes of operation of the forcepsutilizing the end effector configuration of FIG. 6B;

FIGS. 7A and 7B are enlarge views of an alternate embodiment of thelower jaw member according to the present disclosure;

FIGS. 8A and 8B are enlarged views of another alternate embodiment ofthe lower jaw member according to the present disclosure;

FIGS. 9A and 9B are enlarged views of another alternate embodiment ofthe end effector assembly according to the present disclosure showingthe monopolar element in an extended configuration; and

FIGS. 10A and 10B are enlarged views of yet another alternate embodimentof the lower jaw member according to the present disclosure.

DETAILED DESCRIPTION

Turning now to FIGS. 1A-1D, one embodiment of an endoscopic forceps 10is shown for use with various surgical procedures. For the purposesherein, a vessel sealing forceps is shown and described, however, it isenvisioned that other types of forceps or scissors may be utilized whichboth treat tissue for cauterization, coagulation or other purposes andwhich may be configured for monopolar applications as described herein.Moreover, although the figure drawings depict a forceps 10 for use inconnection with endoscopic surgical procedures, the present disclosuremay be used for more traditional open surgical procedures. For thepurposes herein, the forceps 10 is described in terms of an endoscopicinstrument, however, it is contemplated that an open version of theforceps 10 may also include the same or similar operating components andfeatures as described below.

Forceps 10 generally includes a housing 20, a handle assembly 30, arotating assembly 80, a trigger assembly 70 and an end effector assembly100 which mutually cooperate to grasp, treat and divide tissue. For thepurposes herein, the handle assembly 30, rotating assembly, triggerassembly 70 and end effector assembly 100 are only generally described.A more detailed explanation of all of these cooperating elements aredescribed in commonly owned, co-pending U.S. patent application Ser. No.10/460,926 the entire contents of which is hereby incorporated byreference herein.

Forceps 10 includes a shaft 12 which has a distal end 16 dimensioned tomechanically engage the end effector assembly 100 and a proximal end 14which mechanically engages the housing 20. In the drawings and in thedescriptions which follow, the term “proximal”, as is traditional, willrefer to the end of the forceps 10 which is closer to the user, whilethe term “distal” will refer to the end which is further from the user.Details of how the shaft 12 connects to the end effector assembly 100and how the proximal end connects to the housing 20 are explained in theabove-mentioned commonly owned, co-pending U.S. patent application Ser.No. 10/460,926.

As best seen in FIG. 1A, forceps 10 also includes an electrosurgicalcable 310 which connects the forceps 10 to a source of electrosurgicalenergy, e.g., a generator 300. Cable 310 is internally divided intocable leads 310 a, 310 b and 310 c which each transmit electrosurgicalenergy through their respective feed paths through the forceps 10 to theend effector assembly 100 as explained in more detail with respect toU.S. patent application Ser. No. 10/460,926. Preferably, generators suchas those sold by Valleylab—a division of Tyco Healthcare LP, located inBoulder Colo. are used as a source of electrosurgical energy, e.g.,FORCE EZ™ Electrosurgical Generator, FORCE FX™ ElectrosurgicalGenerator, FORCE 1C™ Electrosurgical Generator, FORCE 2™ ElectrosurgicalGenerator, SurgiStat™ II Electrosurgical Generator. One such system isdescribed in commonly-owned U.S. Pat. No. 6,033,399 the entire contentsof which are hereby incorporated by reference herein. Other systems havebeen described in commonly-owned U.S. Pat. No. 6,187,003 the entirecontents of which is also incorporated by reference herein.

Preferably, the generator 300 includes various safety and performancefeatures including isolated output, independent activation ofaccessories. Preferably, the electrosurgical generator 300 includesValleylab's Instant Response™ technology which provides an advancedfeedback system to sense changes in tissue 200 times per second andadjust voltage and current to maintain appropriate power.

Handle assembly 30 includes a fixed handle 50 and a movable handle 40.Fixed handle 50 is integrally associated with housing 20 and handle 40is movable relative to fixed handle 50. Rotating assembly 80 ispreferably integrally associated with the housing 20 and is rotatableapproximately 180 degrees in either direction about a longitudinal axis“A”. Details of the handle assembly 30 and the rotating assembly 80 aredescribed in more detail with respect to U.S. patent application Ser.No. 10/460,926.

As mentioned above, end effector assembly 100 is attached at the distalend 16 of shaft 12 and includes a pair of opposing jaw members 110 and120. Movable handle 40 of handle assembly 30 is ultimately connected toan internally disposed drive assembly (not shown) which, together,mechanically cooperate to impart movement of the jaw members 110 and 120from an open position wherein the jaw members 110 and 120 are disposedin spaced relation relative to one another, to a clamping or closedposition wherein the jaw members 110 and 120 cooperate to grasp tissuetherebetween.

Turning now to the more detailed features of one embodiment of thepresent disclosure as described with respect to FIGS. 1A-3, movablehandle 40 includes an aperture 42 defined therethrough which enables auser to grasp and move the handle 40 relative to the fixed handle 50.More particularly, handle 40 is selectively moveable about a pivot (notshown) from a first position relative to fixed handle 50 to a secondposition in closer proximity to the fixed handle 50 which impartsmovement of the jaw members 110 and 120 relative to one another.

The lower end of the movable handle 40 includes a flange 90 which, uponmovement of the handle 40 proximally, is reciprocated within fixedhandle 50. Flange 90 rides within a predefined channel (not shown)disposed within fixed handle 50 to lock the movable handle 40 relativeto the fixed handle 50.

As best shown in FIG. 1C, a locking flange 44 is disposed on the outerperiphery of the handle 40 above the upper portion of the handle 40.Locking flange 44 prevents the trigger assembly 70 from firing when thehandle 40 is oriented in a non-actuated position, i.e., the jaw members110 and 120 are open. As can be appreciated, this prevents accidental orpremature severing of tissue prior to completion of a tissue seal.

As explained in detail in co-pending U.S. patent application Ser. No.10/460,926, movable handle 40 is designed to provide a distinctmechanical advantage over conventional handle assemblies due to theunique position of the pivot point relative to the longitudinal axis “A”of the shaft 12. In other words, by positioning the pivot point abovethe driving element, the user gains lever-like mechanical advantage toactuate the jaw members 110 and 120 enabling the user to close the jawmembers 110 and 120 with lesser force while still generating therequired forces necessary to effect a proper and effective tissue seal.It is also envisioned that the unilateral design of the end effectorassembly 100 will also increase mechanical advantage.

As best seen in FIGS. 1A and 1D, the end effector assembly 100 includesopposing jaw members 110 and 120 which cooperate to effectively grasptissue for sealing purposes. The. end effector assembly 100 is designedas a unilateral assembly, i.e., jaw member 120 is fixed relative to theshaft 12 and jaw member 110 pivots about a pivot pin 103 to grasptissue.

More particularly, the unilateral end effector assembly 100 includes onestationary or fixed jaw member 120 mounted in fixed relation to theshaft 12 and pivoting jaw member 110 mounted about a pivot pin 103attached to the stationary jaw member 120. A reciprocating sleeve 60 isslidingly disposed within the shaft 12 and is remotely operable by thedrive assembly (not shown) which cooperates with handle 40 as explainedabove to open and close the jaw members 110 and 120. The pivoting jawmember 110 includes a detent or protrusion 117 which extends from jawmember 110 through an aperture 62 disposed within the reciprocatingsleeve 60 (FIG. 1D). The pivoting jaw member 110 is actuated by slidingthe sleeve 60 axially within the shaft 12 such that aperture 62 abutsagainst the detent 117 on the pivoting jaw member 110. Pulling thesleeve 60 proximally closes the jaw members 110 and 120 about tissuegrasped therebetween and pushing the sleeve 60 distally opens the jawmembers 110 and 120 for approximating and grasping purposes.

Once actuated, handle 40 moves in a generally arcuate fashion towardsfixed handle 50 about the pivot point which forces the driving flange(not shown) proximally against the drive assembly (not shown) which, inturn, pulls reciprocating sleeve 60 in a generally proximal direction toclose jaw member 110 relative to jaw member 120. Moreover, proximalrotation of the handle 40 causes the locking flange 44 to release, i.e.,“unlock” the trigger assembly 70 for selective actuation. These featuresare shown and explained in detail with reference to commonly-owned,co-pending U.S. application Ser. No. 10/460,926.

As best illustrated in FIGS. 5A-5C, a knife channel 115 a and 115 b runsthrough the center of the jaw members 110 and 120, respectively, suchthat a blade 185 can cut tissue grasped between the jaw members 110 and120 when the jaw members 110 and 120 are in a closed position. Moreparticularly, the blade 185 can only be advanced through the tissue whenthe jaw members 110 and 120 are closed thus preventing accidental orpremature activation of the blade 185 through tissue. Put simply, theknife channel 115 (made up of half channels 115 a and 115 b) is blockedwhen the jaws members 110 and 120 are opened and aligned for distalactivation when the jaw members 110 and 120 are closed.

As best shown in FIG. 1D, jaw member 110 includes a jaw housing 116which has an insulative substrate or insulator 114 and an electricallyconducive surface 112. Insulator 114 is preferably dimensioned tosecurely engage the electrically conductive sealing surface 112. Thismay be accomplished by stamping, by overmolding, by overmolding astamped electrically conductive sealing plate, by overmolding a metalinjection molded seal plate and/or other ways known in the art. It isenvisioned a trigger lead 311 from switch 200 electrically connects tothe seal plate 112.

All of produce jaw member 110 having an electrically conductive surface112 which is substantially surrounded by an insulating substrate 114.The insulator 114, electrically conductive sealing surface 112 and theouter, non-conductive jaw housing 116 are preferably dimensioned tolimit and/or reduce many of the known undesirable effects related totissue sealing, e.g., flashover, thermal spread and stray currentdissipation.

As best seen in FIG. 1D, jaw member 110 also includes a pivot flange 118which includes protrusion 117. Protrusion 117 extends from pivot flange118 and includes an arcuately-shaped inner surface dimensioned tomatingly engage the aperture 62 of sleeve 60 upon retraction thereof.Pivot flange 118 is also dimensioned to engage pivot pin 103 to allowjaw member 110 to rotate relative to jaw member 120 upon retraction ofthe reciprocating sleeve 60. Pivot pin 103 also mounts to the stationaryjaw member 120 within a proximal portion of jaw member 120.

Preferably, the electrically conductive surface 112 and the insulator114, when assembled, form the longitudinally-oriented knife slot 115 adefined therethrough for reciprocation of the knife blade 185. Asmentioned above, knife channel 115 a cooperates with corresponding knifechannel 115 b defined in stationary jaw member 120 to facilitatelongitudinal translation of the knife blade 185 along a preferredcutting plane to effectively and accurately separate tissue along theformed tissue seal.

Jaw member 120 includes similar elements to jaw member 110 such as jawhousing 126 having an insulator 124 and an electrically conductivesealing surface 122 which is dimensioned to securely engage theinsulator 124. Likewise, the electrically conductive surface 122 and theinsulator 124, when assembled, include longitudinally-oriented channel115 b defined therethrough for reciprocation of the knife blade 185. Asmentioned above, when the jaw members 110 and 120 are closed abouttissue 420, knife channels 115 a and 115 b form a complete knife channel115 to allow longitudinal translation of the knife 185 in a distalfashion to sever tissue along the tissue seal.

As mentioned above, jaw member 120 may include a series of stop members150 a-150 c preferably disposed on the inner facing surfaces of theelectrically conductive sealing surface 122 to facilitate gripping andmanipulation of tissue and to define a gap “G” (FIG. 5A) betweenopposing jaw members 110 and 120 during sealing and cutting of tissue.It is envisioned that the series of stop members 150 a-150 c may beemployed on one or both jaw members 110 and 120 depending upon aparticular purpose or to achieve a desired result. A detailed discussionof these and other envisioned stop members 150 a-150 c as well asvarious manufacturing and assembling processes for attaching and/oraffixing the stop members 150 a-150 c to the electrically conductivesealing surfaces 112, 122 are described in commonly-assigned, co-pendingU.S. application Ser. No. PCT/US01/11413 which is hereby incorporated byreference in its entirety herein.

Jaw member 120 is designed to be fixed to the end of a rotating tube(not shown) which is part of the rotating assembly 80 such that rotationof the tube will impart rotation to the end effector assembly 100. Jawmember 120 is connected to a second electrical potential through therotating tube (not shown) which is connected at its proximal end to alead 310 c from cable 310. Details relating to the mechanical andelectromechanical engagement of the jaw member 120 to the rotatingassembly 80 are described in above-mentioned, commonly-owned, co-pendingU.S. patent application Ser. No. 10/460,926.

As mentioned above, the jaw members 110 and 120 may be opened, closedand rotated to manipulate tissue until sealing is desired. This enablesthe user to position and re-position the forceps 10 prior to activationand sealing. As illustrated in FIG. 1A, the end effector assembly 100 isrotatable about longitudinal axis “A” through rotation of the rotatingassembly 80. It is envisioned that the unique feed path of the triggerlead 311 from the switch 200 through the rotating assembly 80, alongshaft 12 and, ultimately, to the jaw member 110 enables the user torotate the end effector assembly 100 about 180 degrees in both theclockwise and counterclockwise direction without tangling or causingundue strain on the cable lead. The other cable lead 310 c from cable310 is fused or clipped to the proximal end of the rotating tube (notshown) and is generally unaffected by rotation of the jaw members 110and 120. As can be appreciated, this facilitates the grasping andmanipulation of tissue.

Again as best shown in FIGS. 1A and 1C, trigger assembly 70 mounts atopmovable handle 40 and cooperates with the knife assembly 180 (FIGS. 2,3, 4, and 5A-5C) to selectively translate knife 185 through a tissueseal. More particularly, the trigger assembly 70 includes a fingeractuator 71 and a pivot pin 73 which mounts the trigger assembly 70 tothe housing 20. Finger actuator 71 is dimensioned to abut the lockingflange 44 on handle 40 when the handle 40 is disposed in a non-actuatedposition, i.e., the jaw members 110 and 120 are opened.

The trigger assembly 70 is designed to cooperate with a drive bar 64which connects to the knife assembly 180. Proximal activation of thefinger actuator 71 rotates the trigger assembly 70 about pivot pin 73which, in turn, forces the drive bar 64 distally, which ultimatelyextends the knife 185 through tissue. A spring (not shown) may beemployed to bias the knife assembly 180 in a retracted position suchthat after severing tissue the knife 185 and the knife assembly 180 areautomatically returned to a pre-firing position. In addition, when thehandle 40 is actuated and flange 90 is fully reciprocated within fixedhandle 50, the locking flange 44 moves proximally allowing activation ofthe trigger assembly 70.

As best shown in FIG. 1A, the cable 310 is fed through the bottom of thehousing 20 through fixed handle 50. A first lead 310 c extends directlyfrom cable 310 into the rotating assembly 80 and connects (via a fusedclip or spring clip or the like) to tube 60 to conduct the secondelectrical potential to fixed jaw member 120. Second and third leads 310a and 310 b extend from cable 310 and connect to the hand switch orjoy-stick-like toggle switch 200. Switch 200 permits the user toselectively activate the forceps 10 in a variety of differentorientations, i.e., multi-oriented activation which simplifiesactivation. When the switch 200 is depressed, a trigger lead 311 carriesthe first electrical potential to jaw member 110. More particularly, thetrigger lead 311 extends from switch 200 through the rotating assembly80 and along the upper portion of the rotating tube (not shown) andeventually connects to the movable jaw member 110. As can beappreciated, locating the switch 200 on the forceps 10 has manyadvantages. For example, the switch 200 reduces the amount of electricalcable in the operating room and eliminates the possibility of activatingthe wrong instrument during a surgical procedure due to “line-of-sight”activation.

As explained in detail above, the second electrical potential (i.e.,lead 310 c) is conducted to jaw member 120 through the rotating tube.The two potentials are preferably isolated from one another byinsulative sheathing (or the like) which surrounds the trigger lead.Preferably, the jaw members 110 and 120 are electrically isolated fromone another such that bipolar electrosurgical energy can be effectivelytransferred through the tissue to form a tissue seal.

Once the desired position for the sealing site is determined and the jawmembers 110 and 120 are properly positioned, handle 40 may be compressedfully such that the flange 90 is reciprocated and locked within fixedhandle 50. Handle 40 is now secured in position relative to fixed handle50 which, in turn, locks the jaw members 110 and 120 in a closedposition about tissue. The forceps 10 is now ready for selectiveapplication of electrosurgical energy and subsequent separation oftissue, i.e., when movable handle 10 reciprocates within fixed handle50, locking flange 44 moves into a position to permit activation of thetrigger assembly 70 as explained above.

As can be appreciated, the combination of the mechanical advantage ofthe over-the-center pivot along with the assisting compressive forcesassociated with a compression spring (not shown) facilitate and assureconsistent, uniform and accurate closure pressure about tissue withinthe desired working pressure range of about 3 kg/cm² to about 16 kg/cm²and, preferably about 7 kg/cm² to about 13 kg/cm². As mentioned above,at least one jaw member, e.g., 120, may include a stop member e.g., 150a, which limits the movement of the two opposing jaw members 110 and 120relative to one another. Preferably, a series of stop members are toyield a consistent and accurate gap distance “G” during sealing (FIG.5A) which ranges from about 0.001 inches to about 0.006 inches and, morepreferably, between about 0.002 and about 0.003 inches. By controllingthe intensity, frequency and duration of the electrosurgical energyapplied to the tissue, the user can effectively seal the tissue along apredetermined tissue site.

As energy is being selectively transferred to the end effector assembly100, across the jaw members 110 and 120 and through the tissue, a tissueseal forms isolating two tissue halves. At this point and with otherknown vessel sealing instruments, the user must remove and replace theforceps 10 with a cutting instrument (not shown) to divide the tissuehalves along the tissue seal which is both time consuming and tediousand may result in inaccurate tissue division across the tissue seal dueto misalignment or misplacement of the cutting instrument along theideal tissue cutting plane.

The present disclosure incorporates knife assembly 180 which, whenactivated via the trigger assembly 70, progressively and selectivelydivides the tissue along an ideal tissue plane in precise manner toeffectively and reliably divide the tissue. The knife assembly 180allows the user to quickly separate the tissue immediately after sealingwithout substituting a cutting instrument through a cannula or trocarport. As can be appreciated, accurate sealing and dividing of tissue isaccomplished with the same forceps 10.

Once the tissue is divided into tissue halves, the jaw members 110 and120 may be opened by re-grasping the handle 40 which release the flange90 from fixed handle 50. Details relating to the releasing of the flangefrom handle are described in commonly-owned, co-pending U.S. applicationSer. No. 10/460,926.

Tuming now to the operating characteristics of the present disclosureand as seen in the majority of the figures, forceps 10 is designed forboth bipolar electrosurgical treatment of tissue (either by vesselsealing as described above or coagulation or cauterization with othersimilar instruments) and monopolar treatment of tissue. For example,FIGS. 1A-D and 2-4 show one embodiment of a forceps 10 which includes amonopolar element 154 which may be selectively extended and selectivelyactivated to treat tissue. FIGS. 5A-5C show alternate embodiments of thepresent disclosure which shows that the knife 185 maybe extended fromthe distal end of the end effector assembly 100 and selectivelyenergized to treat tissue in a monopolar fashion. FIG. 6A shows anotherembodiment wherein the bottom jaw member 120′ extends distally from thetop jaw member 110′ to allow the surgeon to selectively energize thebottom jaw member 120′ and treat tissue in a monopolar fashion. FIG. 6Bshows yet another embodiment wherein the jaw members 110″ and 120″include tapered distal ends which are selectively energized with asingle electrical potential to treat tissue in a monopolar fashion.FIGS. 7-10B show other configurations of the end effector assemblyand/or bottom or second jaw member which are configured to suit aparticular purpose or to achieve a desired surgical result.

FIGS. 1A-1D and 2-4 show one embodiment wherein a monopolar element 154is housed for selective extension within one jaw member, e.g., jawmember 120, of the end effector assembly 100. More particularly,monopolar element 154 is designed to move independently from knifeassembly 180 and may be extended by further proximal movement of thetrigger assembly 70 (FIGS.1A, 2 and 3) or by a separate actuator 450(FIG. 4).

Preferably, the monopolar element 154 is connected to a reciprocatingrod 65 which extends through an elongated notch 13 in the outerperiphery of the shaft 12 as best seen in FIG. 1B. Drive rod 60 whichactuates the knife 185 extends through the inner periphery of shaft 12.In order to extend the monopolar element 154, the jaw members 110 and120 are initially closed and the knife 185 is advanced distallyutilizing the trigger assembly 70 (See FIG. 2). As best shown in FIG.1C, the trigger 71 is initially advanced to translate the knife 185distally to cut through tissue, i.e., the “cut” stage (shown inphantom). Thereafter and as shown in FIG. 3, the trigger 71 may befurther actuated in a proximal direction to extend the monopolar element154, i.e., the “extend” stage (shown in phantom).

It is envisioned that the trigger assembly 70 may be designed such thatthe monopolar element 154 may be extended when the jaw members 110 and120 are in the open position. For example, the trigger 71 may be moveddistally (or upwardly) from its original, rested, neutral orpre-actuated position to advance the monopolar element 154.Alternatively, the monopolar element 154 may be advanced irrespective ofthe orientation of the jaw ,members 110 and 120. For example, thetrigger assembly 70 could be designed such that the it can be movedlaterally (i.e., perpendicular to the longitudinal axis “A”) to advancethe monopolar element 154 or the trigger assembly 70 could be designedsuch that the monopolar element 154 is extendible when the trigger 71 ismoved to a proximal-most position (i.e., past the “cut” position asdescribed above) and/or when the trigger 71 is advanced distally fromthe neutral or pre-actuated orientation. A return spring (not shown) maybe included to return the monopolar element 154 to a non-extendedposition upon release of the trigger 71.

Upon extension of the monopolar element 154, the generator 300 ispreferably configured to automatically switch the forceps 10 from abipolar activation mode (i.e., deactivating energy delivery to jawmembers 110 and 120) to a monopolar activation mode (i.e., activatingthe monopolar element 154). As can be appreciated, the forceps 10 mayalso (or alternatively) be configured for manual switching between thebipolar activation mode and the monopolar activation mode.

As described above, when the forceps 10 is configured for bipolaroperation, the activation of switch 200 transfers energy from jaw member110 through the tissue and to jaw member 120 to treat tissue. In themonopolar mode, activation of switch 200 (or a separate switch, e.g., afootswitch), transfers energy to the monopolar element 154, through thetissue and to a return electrode 550, e.g., a return pad, placedadjacent to or in contact with the patient. The monopolar activationmode allows the monopolar element 154 to quickly treat avascular tissuestructures and/or quickly dissect narrow tissue planes. Generally, thistype of monopolar activation is common throughout thevariously-described embodiments shown in the accompanying figures.

As can be appreciated, it is also envisioned that the trigger assembly70 may be electrically configured to transmit electrical energy to themonopolar element 154 when extended. For example, the trigger assembly70 may be configured such that proximal-most actuation of the trigger 71(FIG. 1C) both extends and activates the monopolar element 154. Anautomatic safety circuit 460 (or mechanical safety lock (not shown)) maybe employed which prevents the switch 200 from energizing the jawmembers 110 and 120 when the monopolar element 154 is extended.

FIG. 4 shows another embodiment of the present disclosure wherein themonopolar element 154 is selectively extendible utilizing a secondactuator 450. As described above, the knife 185 is advanced by actuatingthe trigger 71 in a generally proximal direction. The monopolar element154 is selectively advanceable independently of the knife 185 and may beextended when the jaw members 110 and 120 are disposed in either theopen configuration or closed configuration. It is envisioned that theactuator 450 may be electrically configured to activate the monopolarelement 154 automatically once extended or manually by activation switch200 or perhaps another switch (not shown). As mentioned above, a safetycircuit 460 may be employed to deactivate jaw members 110 and 120 whenthe monopolar element 154 is extended such that activation of the switch200 energizes the monopolar element 154. In the case of a separateactivation switch for the monopolar element, the safety circuit woulddeactivate the switch 200.

FIG. 5A-5C show an alternate embodiment of the present disclosurewherein the knife 185 can be extended distally beyond the jaw members110 and 120 and separately energized to treat tissue. In this instance,when the knife is extended beyond the jaw members 110 and 120, the knife185 becomes the monopolar element.

For example and as depicted in the activation sequence shown in FIGS.5A-5C, the knife 185 is initially seated in a neutral position duringtissue approximation and grasping and during the sealing process. Oncethe jaw members 110 and 120 are closed about tissue, the elongated knifechannel 115 (defined by upper and lower knife channels 115 a and 115 b,respectively) is formed to allow selective translation of the knife 185through tissue disposed between the jaw members 110 and 120. Uponactuation of the trigger 71, the knife bar 64 forces the knife 185distally through the tissue to the distal end of the knife channel 115.A stop 119 is included to temporarily limit the movement of the knife185 and provide the user with positive tactile feedback as to the end ofthe cutting stroke. Upon further actuation of the trigger 71, the knife185 overcomes the limiting forces associated with the stop 119 and isforced by the knife bar to further extend out of the knife channel 115and beyond the distal ends of the jaw members 110 and 120.

It is envisioned that once the knife 185 extends beyond the jaw members110 and 120, a safety or switch deactivates energizing circuitry to thejaw members 110 and 120 and activates the energizing circuitry to theknife 185 such that activation of the switch 200 energizes the knife 185and the jaw members remain neutral. For example, the stop 119 may act asa safety switch such that upon being forced by the knife 185 out of oraway from the knife channel 115, the stop 119 deactivates circuitry tothe jaw members 110 and 120 and activates circuitry to the monopolarknife 185 and the return electrode 550. A separate lead 69 may be usedto electrically communicate with the generator 300. As can beappreciated, the knife 185 may now be used in a monopolar fashion totreat tissue.

Upon release of the trigger 71, the knife 185 automatically retractsinto the knife channel 115 and back to the pre-actuated position asshown in FIG. 5A. At the same time the stop 119 reverts to its originalposition to temporarily block the knife channel 115 for subsequentactuation.

FIG. 6A shows another embodiment of a forceps 10′ according to thepresent disclosure wherein the lower jaw member 120′ is designed toextend beyond the distal end of jaw member 110′. In order to switch froma bipolar mode of the operation to a monopolar mode, the surgeonactivates a switch or control which energizes jaw member 120′ to a firstpotential and activates a return pad 550 to a second potential. Energyis transferred from jaw member 120, through tissue, and to the returnpad 550 to treat tissue. The distal end of jaw member 120′ acts as themonopolar element for treating the tissue and may be shaped accordinglyto enhance electrosurgical effect.

FIGS. 6B shows yet another schematic embodiment of a forceps 10″according to the present disclosure wherein the distal ends of both jawmembers 110 and 120 are shaped to treat tissue when disposed in amonopolar mode. More particularly, the distal tips 112 a″ and 122 a″ arepreferably elongated or tapered to enhance energy delivery when theforceps 10″ is disposed in the monopolar mode. When disposed in thebipolar mode, the tapered ends 112 a″ and 122 a″ do not effect treatingtissue between electrically conductive plates 112″ and 122″.

A control switch 500 is preferably included which regulates thetransition between bipolar mode and monopolar mode. Control switch 500is connected to generator 300 via cables 360 and 370. A series of leads510, 520 and 530 are connected to the jaw members 110, 120 and thereturn electrode 550, respectively. As best shown in the table depictedin FIG. 6C, each lead 510, 520, and 530 is provided with an electricalpotential or remains neutral depending upon the particular “mode” of theforceps 10″. For example, in the bipolar mode, lead 510 (and, in turn,jaw member 110″) is energized with a first electrical potential and lead520 (and, in turn, jaw member 120″) is energized with second electricalpotential. As a result thereof, electrosurgical energy is transferredfrom jaw member 110″ through the tissue and to jaw member 120″. Thereturn electrode 550 remains off or neutral.

In a monopolar mode, jaw member 110″ and 120″ are both energized withthe same electrical potential and the return pad 550 is energized with asecond electrical potential forcing the electrical current to travelfrom the jaw members 110″ and 120″, through the tissue and to the returnelectrode 550. This enables the jaw members 110″ and 120″ to treattissue in a monopolar fashion which, as mentioned above, advantageouslytreats avascular tissue structures and/or allows quick dissection ofnarrow tissue planes. As can be appreciated, all of the leads 510, 520and 530 may be deactivated when the forceps 10″ is turned off or idle.

FIGS. 7A and 7B show an alternate embodiment of the forceps 10 accordingto the present disclosure which includes a second or bottom jaw member520 which is manufactured such that the distal end 522 a of the tissuesealing surface 522 extends beyond the bottom jaw housing 524. Moreparticularly, in this particular embodiment, the tissue sealing surface522 is preferably made from a stamped sheet metal which is formed atop astamped sheet metal skeleton 530. The proximal end of the sheet metalskeleton 530 may be configured with various pivot points (or apertures),cam slots or grooves depending upon the particular type of pivot actionassociated with the forceps 10. Preferably, a hem or spine 535 extendsalong the skeleton 530 and supports the sealing surface 522 providingadditional strength to the second jaw member 520 (See FIG. 7B). As canbe appreciated, the sealing surface 522 may be supported atop the hem535 by many ways known in the art. An insulating layer 540 is preferablydisposed between the skeleton 530 and the tissue sealing surface 522 toisolate the electrically conductive sealing surface 522 from hem 535during activation. The stamped tissue sealing surface 522 is preferablyformed of a double layer of sheet metal material separated by a slot orknife channel 515 which allows selective reciprocation of a knife 185therein. The distal end 522 a of the tissue sealing surface 522 may bebent 180° to provide a larger conductive surface area which extendsbeyond the jaw housing 524.

It is envisioned that the tissue sealing surface 522 may be curved orstraight depending upon a particular surgical purpose. The jaw housing524 preferably is overmolded to encapsulate the hem 535 of the skeleton530 and sealing plate 522 which serves to insulate surrounding tissuefrom the conductive surfaces of the sealing plate 522 as well as givethe jaw member 520 a desired shaped at assembly.

FIGS. 8A and 8B show another embodiment of the bottom or second jawmember 620 which includes both an electrically conductive sealingsurface 622 for sealing purposes as well as an electrically conductivesurface 632 which is designed for monopolar activation. Moreparticularly, the bottom jaw member 620 includes a jaw housing 624 whichsupports (or encapsulates) a tissue sealing surface 622. A knife channel615 is disposed along the length of the tissue sealing surface 622 andallows reciprocation of a knife 185 therein. An insulating layer 634 ispositioned at or proximal to the distal end of the tissue sealingsurface 622 distal to the knife channel 615. A second conductivematerial 632 (which may or may not be the same material as tissuesealing surface 622) is disposed on the opposite side of the insulatinglayer 634.

It is envisioned that the insulating material 634 will isolate themonopolar portion 632 during electrical activation of tissue surface 622and isolate the tissue surface 622 during electrical activation ofmonopolar element 632. As can be appreciated, the two differentelectrically conductive elements 622 and 632 are connected to electricalgenerator 300 by different electrical connections and may be selectivelyactivated by the user. Various switches or electrical control elementsor the like (not shown) may be employed to accomplish this purpose.Preferably, the tip 632 is substantially blunt to avoid accidentalmechanical cutting or injury.

FIGS. 9A and 9B show another embodiment of an end effector assembly 700according to the present disclosure which includes top and bottom jawmembers 710 and 720, respectively each including similar jaw elements asdescribed above, i.e., tissue sealing surfaces 712 and 722, respectivelyand out insulative housing 714 and 724, respectively. As mentionedabove, the tissue sealing surfaces 712 and 722 of jaw members 710 and720 mutually cooperate to form a knife channel 715 which allows knife185 to be selectively reciprocated therethrough. More particularly, jawmember 710 includes a first part of knife channel 715 a and jaw member720 includes a second part of the knife channel 715 b which align toform knife channel 715.

As best shown in FIG. 9B, knife channel 715 a and 715 b are aligned invertical registration along one side of the jaw members 710 and 720 toallow reciprocation of knife 185 therethrough. Knife channel 715 b ofjaw member 720 is wider (i.e., as measured transversally across thelength of the jaw member 720) and includes a separate channel 715 b 1which is dimensioned to slidingly receive a monopolar element 754therethrough. More particularly, monopolar element 754 is preferablyintegrally associated with knife 185 such that reciprocation of knife185 correspondingly reciprocates monopolar element 754 through channel715 b 1. As can be appreciated, the knife 185 and the monopolar element754 may also be mechanically engaged in a removable fashion such thatthe monopolar element 754 can be added for certain surgical procedures.Obviously, the electrical connections of the monopolar element 754 andthe generator 300 or switches (not shown) would operate in a similarfashion as described above. Preferably, the knife channel 715 b ofbottom jaw member 720 extends to the distal-most tip of jaw member 720to an aperture 756 defined in the tip of jaw member 729 such that themonopolar element 754 is extendable from the jaw 720 upon distalreciprocation of the knife 185. A trigger 70 (or the like) may beutilized as described above with respect to FIGS. 1A-4 to extend themonopolar element 754 for treatment of tissue.

As can be appreciated various switching algorithms may be employed toactivate both the bipolar mode for vessel sealing and the monopolar modefor additional tissue treatments (e.g., dissection). It is alsoenvisioned that a safety or lockout may be employed either electrically,mechanically or electromechanically to “lock out” one electrical modeduring activation of the other electrical mode. In addition, it iscontemplated that a toggle switch (or the like) may be employed toactivate one mode at a time for safety reasons. The monopolar element754 may also include a safety (either mechanical, electrical orelectromechanical—not shown) which only allows electrical activation ofthe monopolar element 754 when the monopolar element 754 is extendedfrom the distal end of jaw member 720.

FIGS. 10A and 10B show yet another embodiment of bottom jaw member 820which may be utilized for both bipolar vessel sealing and monopolartissue dissection or other monopolar tissue treatments. Moreparticularly, jaw member 820 includes an outer jaw housing 824 which isovermolded to encapsulate a tissue sealing plate 822 therein. Tissuesealing plate 822 preferably includes a knife channel 815 forreciprocating a knife as described in detail above. Tissue sealing plate822 also includes a sealing surface 822 a which is disposed in opposingrelation to a corresponding sealing surface (not shown) on the oppositeupper jaw member (not shown).

Tissue sealing surface 822 also includes a sealing surface extension 822b which extends through a distal end 824 a of the overmolded jaw housing824. As can be appreciated, sealing surface extension 822 b is designedfor monopolar tissue dissection, enterotomies or other surgicalfunctions and may be separately electrically energized by the user by ahand switch, footswitch or at the generator 300 in a similar manner asdescribed above. As can be appreciated, the extension 822 b also servesto further anchor the sealing plate 822 in the jaw housing 824 duringthe overmolding process.

Although the general operating components and inter-cooperatingrelationships among these components have been generally described withrespect to a vessel sealing forceps 10, other instruments may also beutilized which can be configured to allow a surgeon to selectively treattissue in both a bipolar and monopolar fashion. For example, bipolargrasping and coagulating instruments, cauterizing instruments, bipolarscissors, etc.

The present disclosure also relates to a method for treating tissue withelectrosurgical energy from the electrosurgical generator 300 whichincludes the steps of: providing an endoscopic forceps 10 including ahousing 20 having a shaft 12 affixed thereto. The shaft 12 includesfirst and second jaw members, 110 and 120, respectively, attached to adistal end of the shaft 12. An actuator or handle assembly 30 isincluded for moving jaw members 110 and 120 relative to one another froma first position wherein the jaw members 110 and 120 are disposed inspaced relation relative to one another to a second position wherein thejaw members 110 and 120 cooperate to grasp tissue therebetween. Amonopolar element 154 is also included which is housed within at leastthe first jaw member 120 and selectively movable from a first positionwithin the first jaw member 120 to a second position distal to the firstjaw member 120. A return electrode 550 is provided and placed in contactwith patient tissue.

The method also includes the steps of: connecting to each jaw member 110and 120, the monopolar element 154 and the return electrode 550 to theelectrosurgical generator 300; grasping tissue between the jaw members110 and 120; selectively activating the jaw members 110 and 120 to treattissue disposed between the jaw members 110 and 120 in a bipolarfashion; and selectively activating the monopolar element 154 and thereturn electrode 550 independent of the jaw members 110 and 120 to treattissue in a monopolar fashion.

Preferably, after the step of selectively activating the jaw members 110and 120 to treat tissue, the method includes the step of: extending themonopolar element 154 from the distal end of the jaw members 110 and120. Advantageously, the step of selectively activating the monopolarelement 154 includes deactivating the jaw members 110 and 120.

After the step of selectively activating the jaw members 110 and 120 totreat tissue, the method may include the step of: releasing the tissuefrom the jaw members 110 and 120.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example, it may be preferable to add other features tothe forceps 10, e.g., an articulating assembly to axially displace theend effector assembly 100 relative to the elongated shaft 12.

It is envisioned that the forceps 10 may be designed such that it isfully or partially disposable depending upon a particular purpose or toachieve a particular result. For example, end effector assembly 100 maybe selectively and releasably engageable with the distal end 16 of theshaft 12 and/or the proximal end 14 of shaft 12 may be selectively andreleasably engageable with the housing 20 and the handle assembly 30. Ineither of these two instances, the forceps 10 would be considered“partially disposable” or “reposable”, i.e., a new or different endeffector assembly 100 (or end effector assembly 100 and shaft 12)selectively replaces the old end effector assembly 100 as needed. As canbe appreciated, the presently disclosed electrical connections wouldhave to be altered to modify the instrument to a reposable forceps.

Moreover, it is envisioned that the switch 200 may be decommissionedduring the cutting process. Decommissioning the switch 200 when thetrigger 71 is actuated eliminates unintentionally activating the forcepsduring the cutting process. It is also envisioned that the switch 200may be disposed on another part of the forceps 10, e.g., the fixedhandle 40, rotating assembly 80, housing 20, etc.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

1-7. (canceled)
 8. An endoscopic forceps, comprising: a housing having ashaft affixed thereto, the shaft including first and second jaw membersattached to a distal end thereof; an actuator operable to move at leastone jaw member relative to the other jaw member from a first positionwherein the jaw members are disposed in spaced relation relative to oneanother to a second position wherein the jaw members cooperate to grasptissue therebetween; each jaw member including an electricallyconductive tissue engaging surface adapted to connect to a source ofelectrosurgical energy such that the jaw members are selectively capableof conducting bipolar energy through tissue held therebetween; and atleast one of the electrically conductive surfaces of a respective one ofthe jaw members extending beyond the respective jaw member, the at leastone electrically conductive surface defining a monopolar element that isselectively activatable independent of the electrically conductivesurfaces of the jaw members to treat tissue in a monopolar fashion. 9.An endoscopic forceps according to claim 8, further comprising a knifethat is selectively moveable within a knife channel defined within atleast one of the first and second electrically conductive surfaces ofone of the first and second jaw members, the knife being selectivelymoveable to cut tissue disposed between the first and second jawmembers.
 10. An endoscopic forceps according to claim 8, wherein themonopolar element includes an insulator on one side thereof to isolatethe electrically conductive surfaces of the jaw members duringactivation of the monopolar element.
 11. An endoscopic forceps accordingto claim 8, wherein the electrically conductive surfaces of the jawmembers are made from a first material and the monopolar elementincludes an electrically conductive surface made from a differentmaterial.
 12. An endoscopic forceps according to claim 8, wherein thesealing surface of at least one of the jaw members includes a spine thatextends along a length thereof, the spine being dimensioned to provideadditional strength to the respective jaw member.
 13. An endoscopicforceps according to claim 8, further comprising a safety that onlyallows electrical activation of the monopolar element when the jawmembers are disposed in a closed configuration.